1. Field of the Invention
This invention relates to a radial-flow turbine wheel for use in rotors for turbo-chargers, gas turbine engines and the like.
2. Description of the Prior Art
A radial-flow turbine wheel consists generally of blades and disc which are usually integrally formed by precision forging or cutting and provided with a spindle passing therethrough. The blades are usually so shaped in consideration of facility in manufacture that upstream portions of the blades are substantially parallel to the spindle and downstream portions are bent as viewed in radial directions. When gas flows through the turbine wheel, component forces of the gas flow acting normal to surfaces of the blades drive the turbine wheel. At the same time, an imbalance of axial component forces of the gas flow produces a net axial thrust force which in turn produces frictional forces opposing rotation with resulting losses of driving forces.